A method and an arrangement for the processing of a material web

(24) Lap day (62) Number of the main application (86) International filing day (86) Filing date for the European patent application (30) Priority information (11) Publication88-05-16 ^number 454 584

83-10-14

82-04-13 . ... . .

____ Application received as:

82-04-13 Swedish patent application □ Completed international patent application with number □ converted European patent application with number (71) Applicant AB Tetra Pak, Box 61 221 00 Lund SE (72) Inventor JER. Lagerstedt, E. Heinonen-Persson, Malmö, Eslöv (74) Agent Bentz C (54) Designation Device for machining a tubular material web (56) Published publications: SE 336 098 (B65B 9/10) (57) Abstract:

Apparatus for processing a tubular material web for converting the same into individual packaged containers. Flexible packaging containers for milk or other beverages are made of tubular material which is filled with the filling material and formed and divided into packaging containers by alternating working forming and sealing jaws (8), which are moved back and forth in the longitudinal direction of the tube (7) and partly in the tube. transverse direction. According to the slopes (8) by means of running in parallel with reciprocating movements.

The DB 647289 invention is both controlled and operated control and drive rods (21, 24), which material tube and are given different

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454 584

The present invention relates to a device for machining a tubular material web by means of two pairs of cooperating sealing jaws arranged on both sides of the web, which are movable back and forth in the longitudinal direction of the material web and partly in the transverse direction of the web of material between the recessed, active position and inset position. , wherein the sealing jaws included in each back pair are pivotally suspended in a yoke, which is driven back and forth in the longitudinal direction of the material web by means of a drive rod arranged parallel to the material web.

Packaging machines for making disposable packages for milk or other liquid fillers are known. The packaging material is usually a flexible laminate comprising layers of paper and thermoplastic and which is supplied to the packaging machine in the form of a web. The packaging laminate is first transformed in the packaging machine into a hose or tube by sealing the longitudinal edges of the laminate web to each other in a liquid-tight longitudinal joint. The laminate tube thus formed is filled with the desired filling material while it is moved substantially continuously downwards through the packaging machine. Thereafter, the tube is sealed in transverse, narrow zones while simultaneously displacing the filler by means of cooperating sealing jaws which are moved towards each other from opposite sides of the tube, compressing it and bringing together the inner thermoplastic layers by simultaneous supply of heat. The process is continuous with the help of two pairs of sealing jaws, which alternately process the tube during simultaneous downward movement and release the tube during an upward return movement. Following the sealing and the resulting tubing of the material tube into individual, closed containers, the containers are separated from each other by incisions in the compressed and sealed zones.

In conjunction with the transverse seal of the tube, a certain reshaping of the tube takes place so that it is reshaped from its original, generally circular cross-sectional shape.

454 584 to a more rectangular cross-sectional shape. This is done by means of forming jaws which are connected to the sealing jaws which compress the tube from two sides to obtain the desired shape. After the separation of the individual, filled and sealed packing containers from one another, further forming molding of the individual packing containers usually also takes place so that they obtain a desired final shape, e.g. parallelepipedic.

In this known type of packaging machine, the movement of the sealing jaws is controlled by means of various cam curves which are arranged in succession on a drive shaft located inside the machine frame, which in turn is connected to an electric drive motor. A number of different cam curves on the drive shaft are connected by means of link and lever systems to the slopes so that they can be driven back and forth according to a predetermined pattern of movement. Thus, by means of various cam curves, the jaws are moved up and down vertically along the longitudinal axis of the tube and partly transversely in an opening and closing movement synchronized with the vertical movement, whereby the jaws during the downward movement are closed and thus, the jaws of the jaws are raised and squeezed upwards. with the slopes in the open, folded position. The movement of the jaws in the vertical direction is controlled by means of fixed guide rails and the various drive movements are transmitted by means of complicated linkage systems, which necessitates a relatively large free space along the jaws of movement. In addition to large space, the steering and drive system also requires careful adjustment to work properly. However, due to the wear that inevitably occurs after a certain operating time, the inaccuracy of the drive arrangement increases again, which can only be counteracted by renewed adjustment and regular service.

It is an object of the present invention to provide a device for machining a tubular web, which device does not suffer from the disadvantages of similar prior art devices.

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It is a further object of the present invention to provide a device for machining a tubular web, which device is of compact construction and includes as few moving parts as possible.

It is a further object of the present invention to provide a device of the above-mentioned type which, during operation, exposes the driving and control means to minimal loads and which, even after a long operating period, works with great accuracy.

These and other objects have been achieved according to the invention by means of a device for processing a tubular material web by means of two pairs of cooperating sealing jaws arranged at both sides of the web, which are movable reciprocally in the longitudinal direction of the material web and partly in the transverse direction of the web of material. active position and precipitated, inactive position, wherein the sealing jaws included in each back pair are pivotally suspended in an yoke, which is driven back and forth in the longitudinal direction of the material web by means of a driving rod arranged parallel to the material web, the characteristics that a second driving rod extends parallel to the first driving rod and via a linkage mechanism is connected to the sealing jaws and arranged to be driven back and forth at such a rate that the difference in motion of the drive rods affects the sealing jaws between active and inactive position.

Preferred embodiments of the device according to the invention have further been given the features of the subclaims.

Since the movement of the slopes is accomplished and controlled by means of the drive rods parallel to the material web, the transmission of power is extremely direct and requires little space. Since both the control and the drive are done by means of the said rods, there are only a few movable drive and control means in the zone of the machine which are often subjected to washing and cleaning for hygienic reasons.

A preferred embodiment of the device according to the invention will now be described in more detail with particular reference to the accompanying schematic drawings which merely show the details necessary for understanding the invention.

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Fig. 1 shows schematically in perspective the contours of a packaging machine, the path of the material path through the machine being indicated.

Fig. 2 also shows in perspective the part of the packaging machine according to Fig. 1 in which the transformation of the packaging material tube into individual packaging containers takes place.

Fig. 3 is a front elevational view of a part of the forming and machining arrangement of Fig. 2.

Figs. 4A and B show the arrangement of Fig. 3 from the side, the sealing jaws being shown in different machining modes.

The packaging machine 1 shown in Fig. 1 comprises at its rear, lower part (left in Fig. 1) a magazine in which a packing material web 2 in the form of a roll 3 is located. The packaging material is a conventional packaging laminate comprising a central support layer of paper, layers of aluminum foil and outer layers of liquid-tight and heat-sealable plastic material, usually polyethylene. From the magazine, the web of material 2 runs through a number of break and guide rollers 4 to an upper part of the packaging machine where various unimportant machining of the web 2 takes place in this context, such as application of opening devices, embossing of big lines and sterilization. In the upper part of the machine, the material web 2 further passes register holding means 5, which in a known way engage with the transverse big lines present in the material web and ensure that the processing of the material roller web takes place in registers with said big lines. After passing the upper part of the machine, the packaging material web is guided substantially vertically down along the front of the machine (to the right in Fig. 1). At the same time, with the aid of non-shown guide rollers and a tube forming device 6, a gradual conversion of the material web to tube shape is made. The two longitudinal edge zones of the material web will overlap each other and the longitudinal joint elements invisible in Fig. 1, which are not visible in FIG. 1, are heat sealed to each other so that a material tube 7 with a longitudinal, liquid tight joint is formed. During continued, downward movement through the packaging machine 1 is filled

454 584 material tube 7 with the desired filling material. At the lower end of the tube there is a machining or molding arrangement including sealing jaws 8 and molding flaps 9 (Figs. 2-4) which process the packaging material tube and transform it into filled and sealed packaging container blanks 10, which will be described in more detail below. The thus-formed packaging container blanks 10 are then separated from the material tube 7 and passed down to a final wiper 11 located at the front end of the packaging machine 1, in which they are guided by a conveyor 12 past a number of processing stations in which a final forming processing of the packaging container blanks 10 finish formed, mainly parallelepipedic packaging containers 13 can be discharged from the packaging machine for further promotion for packaging in trays and transport to points of sale.

The machine shown in Fig. 1 is only one example of a preferred machine type in which a device according to the invention is useful. Thus, the packaging machine 1 may also be of a different, previously known main form and the path of the packaging material web 2 through the machine need not be the one shown. It is essential that the packaging machine only works with packaging material in the form of a continuous web 2, which is continuously transformed into a tube 7 which is filled with filling material and molded.

Fig. 2 shows on a larger scale part of the packaging machine 1 according to the invention. The front part of the packaging machine 1 comprises a device for machining and forming the material tube 7 which runs vertically downwards through the machine. In the lower part of the packaging machine 1 there is a motor and gear arrangement 14 driving a horizontal drive shaft extending horizontally through the machine, on which a number of radial cam curves are arranged. Of importance to the device and method of the invention is primarily a first radial cam curve 16 and a second radial cam curve 17. As is particularly clear from Figures 2 and 3, the machine comprises

454 584 according to the invention a left and a right half, which are identical but mirrored. For the sake of clarity, the description will, where appropriate, only be directed to a machine half, while it is understood that the opposite machine half is designed and operates in a similar manner. Thus, of the two cam curves 16, 17, there are two sets, and on both sides of the motor and gear assembly 14, the arrangement is such that the first cam curve 16 is closest to the assembly 14 while the second cam curve 17 is further out towards the end of the main drive shaft 15 , as clearly shown in Fig. 2.

Both above and below the cam curves 16,17 there are arms 18,19 which, via curving rollers, abut against, respectively, cam curve 16,17. More specifically, the arm 18 is arranged above the first cam curve 16 and with its one end pivotally supported around a pivot axis parallel to the main drive shaft 15. The arm 18 is connected at its free end via a linkage system 20 to a first driving rod 21 extending vertically through the machine, which in turn is connected to the forming assembly 22 of the machine, which will be described in more detail below.

The arm 19 abutting the second cam curve 17, like the arm 18 at one end thereof, is pivotally mounted around a pivot axis extending parallel to the main drive shaft 15. However, the arm 19 is located below the second cam curve 17 against which it abuts via a rotatably mounted pulley in the arm 19. At the front end of arm 19 (left in FIG. 2), like the arm 18, via a linkage system 23, the arm 19 is connected to a driving rod extending vertically through the machine, namely a second driving rod 24.

At some distance from the front ends of the two arms 18, 19, a toothed belt or other traction receiving member 25 extends between a bracket on the lower arm 19 and a rotatably mounted pulley 26. On the pulley 26, which serves as a break roller for the toothed belt 25 extends the toothed belt via a further, mounted on upper arm 18

454 584 pulley 27 to one end of a lever 28, to which it is connected via a helical tension spring 29. At the opposite, mirrored side of the machine, there is a similar timing belt which in turn is connected to the other arm of the lever 28 via a second spring. By means of the springs 29 and the lever 28, the toothed belt 25 exerts a cohesive force via the pulleys on the upper lever 18 and the bracket in the lower lever 19, which presses the two levers against each other, so that they are constantly in contact with the cam curve 16,17. The different movements of the two levers 18,19 are taken up by the spring 29 and the lever 28, which, due to the alternate working modes of the two machine halves, will perform a swinging motion.

The arrangement of holding the two arms 18,19 in contact with spring curves 16, 17 with spring loaded, traction absorbing means 25 is very space saving and reliable. Only the traction receiving means need be present in the immediate vicinity of the cam curves and the drive assembly, and the spring assembly 28,29 may be located at any other suitable location in the machine. In the preferred embodiment, the two interchangeable machine halves can be connected to the same spring assembly via different timing belts if this is designed as a pivotal lever 28. This saves additional space while allowing the alternate utilization of the spring means 29 to reduce their size by about 50% simultaneously the spring characteristic is improved due to the shorter spring length.

As previously mentioned, the two arms 18,19 are connected by means of the respective link systems 20,23 to the vertically arranged drive rods 21 and 24. The drive rods 21 and 24 are vertically slidably mounted in sliding bearings 30 in the frame of the machine, and the two link systems 20,23 are formed. to transmit the swinging movement of the two arms 18,19 without lateral influence to the drive rods 21,24. This is made possible by means of multi-link systems, which, however, are of a conventional type and therefore should not need to be further described in this context.

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As previously mentioned, the two mirror-facing alternating forming assemblies of the machine comprise, inter alia, sealing jaws 8 and mold flaps 9. Each forming assembly 22 includes, in particular, a yoke 31 which is at one side rigidly connected to the first drive rod 21 and movable vertically upwardly and downwardly by means. of this. The second drive bar 24 extends through the yoke without being in direct contact with it. On either side of the two drive rods 21, 24, the yoke 31 is provided with storage shafts 32 for the two sealing jaws 8. The shafts 32 extend perpendicularly to the drive rods 21,24 and parallel to the main drive shaft 15. The sealing jaws 8 are pivotable about the shafts 32 between an inactive outer or pivoted position and an active, pivoted position in which the sealing jaws 8 extend substantially parallel to the drive rods 21, 24 (Fig. 4). The sealing jaws 8 are actuated between inactive and active positions by means of the second drive rod 24, which in the space between the two sealing jaws 8 opposite one another carries a bracket 33. From the bracket 33, links 34 extend downwardly to arms 35. , which protrude from the lower portions of the sealing jaws 8 towards each other. This construction causes the sealing jaws 8 to remain motionless as long as both the first and second drive rods 21 and 24, respectively, are moved uniformly, while any difference in the two drive rods 21 and 24 movement moves the bracket 33 vertically up or down relative to the yoke 31 so that the sealing jaws 8 are pivoted around the shaft shafts 32. The arrangement diagram of the device will be described in more detail below.

At the upper portions of the two sealing jaws 8 there are laterally projecting arms 47 which are located opposite and on either side of the material tube 7 extending vertically through the packaging machine 7. The arms 47 facing each other transverse to

454 584 packing material tube 7 extends sealing rails 36 (Fig. 4) which are arranged in the active position of the sealing jaws 8 to compress the packing material tube 7 in a transverse zone. One of the two cooperating sealing rails 36 has two electrically spaced apart conductors. by heating the thermoplastic layers of the packaging material, there is arranged to seal the tube in transverse, spaced apart zones. The sealing rails 36 are connected in a known manner to a suitable power source.

Between the two conductors of the sealing rail 36, a cutting device not visible in the figure operates, which when the sealing has taken place, activates and cuts the packaging material tube between the two transverse seals. The cutter is of known construction and is hydraulically operated by means not shown. Furthermore, there are not visible so-called volume flaps which influence the forming of the packaging containers and are operated mechanically by means of pressure rods arranged in the sealing jaw 8 which are actuated via a control arm 37 supported by a curve 38 supported by the machine's stand, in the vertical, reciprocating movement of the sealing jaw.

On either side of the sealing rails 36 of the sealing jaws 8 there are hook means 39,40 which in the active position of the sealing jaws 8 are connected to each other and provide the necessary strong pressing of the sealing rails 36 against each other during the compression of the tube and the sealing process. More specifically, one of the sealing jaw includes a fixedly mounted, perpendicular projecting hook member 39, while the opposite sealing jaw has a hook member 40 which is pivotable about a shaft extending parallel to the main shaft of the machine and partly movable back and forth by means of a sealing jaw provided. and cylinder assemblies 41. The vertically oscillating movement of the hook member 40 is provided by means of a cam curve 42 projecting laterally from the aforementioned bracket 33 mounted on the second drive rod 24.

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The connection between the bracket 33 and the sealing jaw 8 via the links 34 and the arms 35 provides such an exchange that the upward movement of the second drive rod relative to the yoke 31 not only precipitates the sealing jaws 8 from active to inactive position, but also via the cam curve 42 the hook-shaped member 40 lifts out engagement with the cooperating hook member 39. In the downward movement of the second drive rod 24 relative to the yoke 31, in the opposite manner, the sealing jaws 8 are pivoted from the pivoted or swiveled position shown in Fig. 4A to the pivoted or active position shown in Fig. 4B. At the same time, the hook member 40 is lifted by the hook cam curve 42 so that the engagement with the hook member 39 can be effected without hindrance. After the engagement is completed, the piston and cylinder assembly 41 is activated, which results in the hook member 40 being slightly retracted, ie into the sealing jaw 8 so that the desired compressive force arises between the two sealing rails 36. The piston and cylinder assembly 41 is kept activated during the entire sealing and cutting process and is released immediately before starting the eversion of the sealing jaws 8 to the inactive position.

Above the sealing rails 36 of the sealing jaws 8 are the aforementioned mold flaps 9. The mold flaps 9 have a substantially U-shaped cross section from above and together form a rectangular channel whose internal dimensions correspond to the desired outer dimensions of the finished packaging container. The two mold flaps 9 are pivotally suspended around pivot shafts, which are located slightly above the sealing rails 36 and extend parallel thereto. At the upper end of the mold flaps 9, laterally projected axes with guide blades 43, which engage in downward movement of the yoke 31 with the mold flap curves 44 supported by the machine frame and guide the mold flaps 9 to abut against each other from the sides of the packaging material tube 7. The mold flaps 9 are spring-loaded from spring. 7 to be in a predetermined, undirected position at the yoke 31

454 584 upward return movement. The mutual position of the mold flaps determines, as previously mentioned, the shape of the finished packaging container and thus also its volume. Volume adjustment can therefore be done by lateral movement of the mold flap curves 44, and these are therefore pivotally suspended in the machine frame and are maneuverable in direction towards or away from each other by adjusting the volume of the packaging containers.

During operation of the machine, the packaging material web 2, as previously mentioned, is supplied in the form of a roll of material 3 which is inserted at the rear end of the machine. From the material roll 3, the material web 2 runs past a number of break and guide rollers 4 and register holders 5, which control the web and ensure that the web's line or print pattern is in the correct position in relation to the machining operations performed in the machine. The processing operations are partly of conventional type, such as, for example, application of opening devices, printing of dates and shaping and cutting of finished packaging containers. After the material web 2 has reached the front, upper part of the packaging machine (to the right in Fig. 1), the web is mainly led vertically downwards while it is transformed into a tube with overlapping longitudinal edges by means of the tube forming means 6. The two longitudinal edges are sealed by means of sealing means located at the tube forming member 6 so that the material tube 7 is completely sealed with liquid. The pre-formed material tube 7 then extends downward to the part of the machine which processes the material tube and transforms it into individual, filled packaging containers. After the packaging material tube 7 has passed a pair of cooperating guide rollers 46 which are level with the surface of the liquid column inside the packaging material tube, the material tube comes into contact with one of the two forming assemblies 22 which alternately process the tube. More specifically, one of the forming assemblies 22 comes after using the first one

454 584 drive bar 21 is moved to its upper turning position (left in Fig. 3, by means of the sealing rails 36 of the sealing jaws 8 to compress the packing material tube 7 in a transverse zone. The vertical drive of the sealing jaws 8 is partly effected by means of the first drive rod 21 which is rigidly connected This moves in a reciprocating, vertical movement in which both the sealing jaws 8 and the other parts associated with the yoke are moved. By means of the second drive rod 24, the sealing jaws 8 provide a pivotal movement between their swung open end position and the closed active position (Fig. 4). Since the drive rod 24 via the bracket 33, the links 34 and the projecting arms 35 of the sealing jaws 8 are connected to the sealing jaws, these will be imparted a transverse pivotal movement as soon as the drive rods 21,24 move uniformly. Thus, the sealing jaws 8 are moved from their inactive position to their active position by giving the second drive rod 24 while the forming assembly 22 is at its upper turning position a downward movement relative to the first driving rod 21, which movement via the links 34 pivots the arms 35 of the sealing jaws 8 downwardly since the sealing rails 36 are pressed against each other from both sides of the material tube 7.

In other words, the oscillating movement of the two sealing jaws 8 can be said to occur because the other drive rod 24, which is connected to the sealing jaws not only performs the same reciprocating movement as the driving rod 21 but also has a movement superposed on this movement, as well as reciprocating movement. The resulting difference in motion between the two drive rods regulates the transverse movement of the sealing jaws so that during most of their downward movement they are in the retracted, active position so that during most of their upward movement they are in the folded, inactive position.

When the sealing jaws 8 are pivoted to their active position, the hook member 40 is lifted by means of the previously described hook hook curve 42 arranged on the bracket 33 so that the hook member 40 in

454 584 the active position of the jaws engages with the hook member 39. Immediately after the engagement, the piston and cylinder assembly 41 connected to the hook member 40 is actuated by supplying pressure fluid so that the hook means is pulled backwards, i.e. into the sealing jaw 8 causing a predetermined, correct bearing pressure between the jaws 36 . The required relatively high pressure is hereby absorbed entirely by the hook-shaped members 39,40, which greatly relieves the sealing jaws 8 and their suspension, which is advantageous for both the construction and the operational safety. with predetermined abutment pressure, are pressed against each other for a certain part of the time they are in the closed position. In this way, it is ensured that the fill material present in the sealing zone is completely displaced at the same time as a good contact between the laminate surfaces to be sealed to each other and a satisfactory heat transfer is promoted.

After the yoke 31 has left its upper turning position, the two mold flaps 9 will, with their guide blades 43, run into the mold flap curve 44, which, against the action of the spring flaps of the mold flaps, causes the mold flaps to move into contact with one another and reshape the portion of packaging material existing between the flaps 7 substantially rectangular cross-sectional shape which corresponds to the desired cross-sectional shape of the final package. The position and pressing pressure of the mold flaps 9 can be regulated by lateral movement of the mold curves 44 which is effected by means of the volume knob 45 arranged at the upper suspension point of the curves.

After the yoke 31 has been moved down a certain distance by means of the first drive rod 21, the operating arm 37 of the invisible volume flap comes into contact with the curve 38 arranged in the frame, which causes the volume flap to be actuated to the desired position. At the same time, the hydraulic cylinder for the mower is actuated to cut the material tube in the

454 584 compressed the area between the two of the sealing rails provided by the seals.

As the forming assembly 22, as described, is moved downwardly during tightening and sealing of the packaging material tube 7, the opposite mirror-facing forming assembly 22 moves upward. By a suitable positioning relationship between the two drive rods 21,24, it is hereby ensured that the sealing jaws 8 are in the folded position so that the sealing jaws 47 of the sealing jaws can pass freely outside the simultaneously descending, activated arms 47 of the opposite forming assembly.

As the current forming assembly 22 approaches its lower turning position, the pressure fluid supply to the piston and cylinder assembly 41 is interrupted whereby the pulling force of the hook member 40 ceases and the compressive pressure between the two sealing rails 36 relieves. By actuating the second drive rod 24 and moving the same in an upward direction relative to the first drive rod 21, the bracket 33 and the associated hook curve 42 are lifted, which causes the hook member 40 to be lifted out of engagement with the hook member 39 while simultaneously swinging the sealing jaws from active to inactive. mode begins. At the same moment, also the guide blades 43 of the two mold flaps 9 have left the lower end of the mold flap curve 44 and the mold flaps 9 have been moved to the outwardly turned outward position due to their spring load. When the sealing jaws 8 have reached their outwardly pivoted inactive position, the relative movement between the two drive rods 21,24 ceases and they simultaneously begin to move upwards, which causes the forming assembly 22 to move upwardly with the sealing jaws 8 in the swiveled position, whereby 22 active, downward arms 47.

The described process is continuously repeated during operation and the two forming assemblies process and progressively package the packaging material tube 7. As the sealing jaws 8 at the lower end of the forming assembly work open and

454 584, the packing material tube releases the newly formed packing container blank 10 of its own weight freely downward into a slide not shown, which transfers blank 10 to the end winder 11 where the corner of the mainly pillow-shaped blanket 13 is opened so that parallelepipedic packing containers 13 are provided.

The design of the sealing rails 36 can be varied depending on the type of packaging material used. Typically, a laminate-type packaging material is used which comprises layers of fibrous material, usually paper, and outer thermoplastic layers. In this type of material, the sealing rail 36 conveniently includes electrical resistance wires which are connected to a current source during the sealing. In the manufacture of aseptic packaging containers, ie packaging containers for long-lasting sterile fillers, a packaging laminate is used which, in addition to layers of paper and thermoplastic, also includes layers of metal foil. For such material, the sealing rails 36 in the working surface may comprise an electrical conductor which is connectable to an electrical conductor. AC source. Upon sealing, a magnetic field is induced in the metallic foil of the packaging laminate opposite the sealing rails, which losses due to the aluminum foil result in both the foil and adjacent thermoplastic layers so that they can be heat sealed to each other.

The device according to the invention makes it possible to carry out the processing and reshaping of the packing material tube filled with bulk goods in a very limited space. By the absence of external links for power and motion transmissions to the forming units, these can be given a very compact design. The absence of complicated linkage arrangements in the molding area is also a significant advantage in especially aseptic machines, since the necessary, frequent washing and cleaning of the forming assemblies can be undertaken without exposing the drive assembly and its storage and lubrication points to detergent.

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Since the entire drive unit is outside the so-called disk zone, a long service life combined with low lubricant consumption is ensured.

By using the vertical drive rods both as guides for controlling the movement of the forming units and as rods for transmitting the drive, the construction becomes extremely simple and reliable compared to known, similar arrangements.

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